In the copending application referred to above, the disclosure of which is incorporated herein by reference, there is described a process and composition of matter for preserving green coloured plant tissue while retaining the natural green colour thereof, in which the tissues are immersed in a solution comprising 30-70% by volume water; at least one monohydric alcohol; at least one preservative component selected from the group comprising lower carboxylic acids, and di and trihydric alcohols, and sufficient buffering and mordant reagents to control the pH and osmolality of the solution so as to permanently retain the green colour in the tissues. Within this general description of the treatment solutions which is suitable for almost all kinds of green leaves, we have found that certain green tissues such as ferns, grasses, lichens, mosses salal, and certain coniferous needles are best treated with modified or special solutions particularly formulated for their special requirements.